Glaucoma is the leading cause of irreversible blindness in the United States and the world. Its mechanisms of action are not fully understood but the end result is a progressive loss of retinal ganglion cells, which are the cells that communicate visual information to the brain. To learn why retinal ganglion cells are selectively targeted, researchers use animal models in which the internal pressure of the eye is raised experimentally since ocular hypertension is a common symptom of the disease. Several models have gained widespread use over recent decades, producing an explosion of insights into glaucoma etiology and pathophysiology. Continued progress is hampered though by issues which plague current methods of pressure elevation on multiple fronts. Most significant of these are the efforts spent treating animals that fail to develop ocular hypertension, measuring intraocular pressure by hand on a frequent basis, and pooling data to overcome variability in the amount and time course of pressure changes. This project puts forth an innovative system of glaucoma induction and regulation that is ground-breaking in its promise of near-zero failure rate, near-constant pressure changes, and near-effortless pressure reading. The system has the potential to not only accelerate research advances from animal glaucoma models, but also to arm clinicians with a new tool for arresting progression of the disease in humans for whom existing methods have been exhausted. The specific aims of the project are: i) to implement a tethered and head- mounted version of the proposed system for use on rats and ii) to evaluate the long-term performance of the system with intraocular pressure measurements, electrophysiological recordings, and ocular imaging on live rats. The overall goal is to apply the research tool to the rat glaucoma model in order to address questions that are otherwise difficult to answer experimentally, like how does the outflow capacity of the living eye and the physiological properties of its optic nerve cells change as glaucoma progresses. In so doing the project will help speed progress in the fight against this debilitating disease.